5.10.5. String Collating Support
If the sorting rules for your language are too complex to be
handled with the simple sort_order[] table,
you need to use the string collating functions.
The best documentation for this is the existing character sets.
Look at the big5, czech,
gbk, sjis, and
tis160 character sets for examples.
You must specify the
strxfrm_multiply_MYSET=N
value in the special comment at the top of the file.
N should be set to the maximum ratio
the strings may grow during
my_strxfrm_MYSET
(it must be a positive integer).